Originally bought mine back in 1986, used mostly on an MX during my 35mm SLR days.

This lens was part of the reason I stuck with Pentax for a DSLR, I had a number of good legacy primes that I wanted to recycle, this one at the top of the pile.

Colour, contrast, sharpness -all there, all excellent. Shame to lose the 180 degree FOV that the lens provided on 35mm film, but it's still plenty wide. I've been playing around with some 'de-fisheye' options out of curiousity and found that Raw Therapee handles this superbly -there's a little loss of FOV but nothing else seems to suffer. The two attached shots show pre and post correction.

This little lens is my DA15 remedy as my wallet won't allow any lenses in the Limted's price range for a while - and now I don't need it! Field of view edge-to-edge is between 14 and 15mm as tested against those DA primes. Color and contrast match up great against any lens I've used since 1975 (which is about when this was made). Mine is marked 1:4/17 - I have also owned the '1:4 17' version and both performed really well. This one is in slightly better condition overall. Another 9.5 on my scale

Close focus is great fun and really makes items stand out from the background, and bokeh in those conditions is neither incredible nor indifferent.

As Bojidar Dimitrov’s wonderfully informative K Mount website reveals, there are two versions of this lens. Version 1 was in production 1975-1977 and version 2 1977-1985. You can tell the difference between them easily enough. The front of version 1 has ‘1:4/17’ written on it, version two has ‘1:4 17mm’ on it. The metal plate affixed to the rear element is also slightly different (on version 2 it is attached by what looks to be two small rivets). The overall grading I give to this lens is for version 2. I have owned two copies of each of these over the years, which must mean I like this lens – and I now possess only one copy. In my experience, the two versions offer slight differences in image quality. Both have excellent colour and contrast. Version 2, however, is perhaps sharper at all apertures. Both my copies of version 1 offered rather hazy softness at f4, with stopping down to f8 usually necessary to get reasonable detail on digital. This is not to say that the image quality was not very good – it was superior to the detail revealed by the kit lens at 18mm. Both copies of version 2 I've had have been sharper, however - very sharp wide-open and even sharper stopped down. Version 2 also seems to exhibit less susceptibility to flare, which may possibly explain why it exists: the later one was intended to be an improvement over the earlier. On film such differences do not amount to much at all, but on digital they become more noticeable. Whichever copy you end up owning, this must count as one of the finest Pentax lenses ever made. It is very compact indeed. Its build-quality is superb. Its field of view on full-frame is jaw-dropping when encountered through the detailed, luminous and large viewfinder screens on film cameras such as a Pentax MX or ME Super (although both offer only a 92% view). On current digital crop the 17mm still remains in the ultra-wide category. It is perhaps slightly less wide than the DA10-17mm fisheye at 17mm, but there is nothing much in it and the 17mm f4 is a fraction of the size; it is also significantly wider than the 18mm kit lens and noticeably wider than the 16mm end of the DA16-45. There is some fisheye effect even on digital, but that is easily straightened out in post-processing if needs be. It has built-in filters, which is useful. Some people have expressed worries about the vulnerability of the exposed but actually quite small front element. This is inevitable with a fisheye, but I have never heard of anyone actually damaging the front element – and the metal lens cap reflects the standard of construction of the lens itself by providing solid protection. Using this lens is always a pleasure.

I bought this lens as a wide angle to use on digital. I like it so much I thought Id better add a review.
As stated above build quality is great and mine is in excellent condition.
On APSC the fish-eye is mild but can be used to good effect.
I havent had any flare problems, IQ is good and no CA problems. It is a bit soft at f4 but very sharp at f8. I tend to leave it at f8 and focus by just estimating distance and using the calibrations on the focus ring. This is quick and simple.
Because it is very small, it is easy to include and I find it more useful than you might expect.
Mostly I like this lens because of the way it captures landscapes. A couple of quick images below:

I bought this lens to use on a film camera. It was the first time I've ever used a fish-eye, and wow, was I surprised! It's extremely wide on film, and the perspective is absolutely unique! I've spent the first day with it taking portraits of friends (on film), and the results are absolutely hilarious! When I showed the pictures to my friends, we were rolling on the floor laughing. (I would upload some samples, but they'd probably kill me if I did)

At f/4, the image in the viewfinder is a bit darker than what I was used to, but you can still achieve focus for indoor shots. The focusing mechanism is nice and smooth, with a short throw, but that's enough for this focal length.

I haven't really stress-tested the lens to check sharpness and aberrations at all apertures. I've only shot around f/8 so far, and images come out nice and crisp. I gave it a 9 for sharpness (although I haven't tested it at f/4).
For aberrations, you get a bit of flaring, if the sun is in the picture, but I guess that's normal.
Bokeh? It's a fish-eye. You probably don't buy this for bokeh, but you can blur the background, as long as the foreground is very close (otherwise, why put a focus ring on it in the first place?)

Handling is typical of old lenses (which means very good), just be careful about the exposed front element. It's also very small (unlike the Samyang 8mm fish-eye for cropped sensors), so it's easy to carry around.

I haven't used this lens much on digital.On my K20D, the FOV in the viewfinder is wider than that of the 18-55 @ 18mm, and you can see the barrel distortion typical of a fisheye. If that is what you want, then you should be happy, the image quality is great.

Here's also a low-resolution scan of what it can give on film:
This low-res scan doesn't do it justice, but the original 20x30cm print looks magnificent! Sure, you can see a bit of flare, but hey, the freakin' sun was in the frame!

In conclusion: for film, this lens is excellent! I don't think I'll ever sell it, it's just so fun to use!

I bought this lens on e-bay UK about a year ago. I was in two minds about purchasing it as I was not sure how the FishEye would work out for me as nearly always I end up in squishy places with no room to maneuver.

I dislike changing lenses in the field and generally just place a lens on the K200D for the day and that's it. Of course the inevitable happened and I was caught in a 18th century town in Germany where my M28 was just not wide enough and I did not have my Sigma 10/20 with me so on went the FishEye. I was expecting a total disaster with curved straight lines but actually they weren't that bad and I can live with the results. If you have a horizontal straight line in the scene it's going to curve up or down if it's not dead centre on the lens.

Manual focusing on cameras not designed for it can be a little tricky, folk law says that with ultra wide angles everything will be in focus pretty much from the camera to infinity. Well the confirm focus lamp can blink away but to be sure and to get the best out of this lens I think you need to stop down two stops or so. Compared to the Sigma 10-20 I don't think it's quite as sharp as the Sigma but that's just an on-screen comparison, no detailed test, it is however, a lot easier to carry around.

In theory with an APS-C sensor having a crop factor of 1.5 this 17mm lens should work out around 25.5mm but it doesn't. Mounting my K200d on a tripod with the 17mm attached I noted it's field of view in my living room, exchanging this for the Sigma 10-20 and zooming until it covered the same field of view, it came in around a shade more than 14mm according to the scale on the Sigma.

I finally bought one of these on eBay after stalling many times (telling myself I would only find very limited use for it, being a fisheye). I was tempted by the bargain price and knowing I could always resell it if disappointed.

News flash: I'm definitely not reselling. It's great. I wish I got one earlier. On APS-C crop format the fisheye effect can be almost unnoticeable with careful composition, and can really add something in dramatic wide perspectives. Just a little soft wide open but by f8 its pin sharp and almost everything is in focus, I have got into the habit of leaving it set on the hyperfocal marks (orange) and just shooting. Not something I'd do with any other lens I own.

Others have commented on the flare issue but its not been noticeable to me so far, I did 'stress test' with a few 'into-the-sun' shots and didn't have a problem.

I took the "glass lasts, bodies come and go" advice seriously, and made this lens my first Pentax purchase (used, from a forum member)--I bought it before I ordered my K-7, even.

What others have said regarding this lens is true. It's very good, and it's not particularly easy to find, so it's pretty much a keeper.

What I really like about the K 17/4 is its color rendition and its versatility. On the K-7, if used carefully, it can yield fairly wide-angle images with only moderate hints of its rectilinear fisheye nature. Mounted on my MX, its true essence is revealed: a wide view with some very interesting effects.

Those looking for a full-on fisheye would be disappointed with this lens, even on a film body. But if you're looking for something that can handle landscape photography and give you some interesting perspectives, the K 17/4 might be just what you're looking for.

It's hard for me to think of this lens's moderate distortion as a negative, though: after all, it's a rectilinear fisheye. To count that as a con seems akin to complaining that a more normal lens doesn't yield a fish-eye view, or that an M 50/1.4 isn't a 1:1 macro. It is what it is.

As others have noted, its build quality is very high. The only negative with this lens is that the front element is open to everything out there. (I've thought of possible ways to protect it with a clear filter, but haven't actually tried any of them. If the lens were on my K-7 every day, I might very well put my ideas into action, but . . . well, I just try to be extra careful instead.)

Again, this lens isn't for everyone, but it has its niche, and it fills that niche extremely well.

With this lens my search for a relatively affordable wideangle ended (so far). Like all M and K lenses, it's very well built and a pleasure to use. The ring to switch the inbuilt filters seems also very reliable; when shooting on digital, i guess only the skylight and uv filter are very useful (the other ones are nice on black and white though).
It's a compact lens, which is very important for me, and the reason why i wouldn't buy a wide angle zoom. With this lens (as with other primes), you remain rather discreet. Add to that the extremely wide angle of view, and you have a fine lens for shooting people discreetly (you don't have to point the camera at them, but they'll still be in your frame).
As long as you don't have straight lines towards the edges of your frame (on digital), this lens makes for a fine wide angle, without a very annoying distortion. Of course, if you would want the distortion, there's endless fun to be had with the curves this lens can produce. I guess this makes it a horrible lens for architecture, but it does very well for landscapes, cityscapes and street- or people shots without too many walls or straight lines.
At a maximum aperture of f4, it's indoor use is fairly limited though, and as this lens is made for a wide depth of field, there's no playing with the bokeh. Then again, that's not what you get this lens for. And the slowness is compensated by it's short focal length, allowing you to use longer shutter speeds handheld. So it levels out very acceptably

Slow f/4, a bit too small resulting in unwanted fingers in the frame and no lens protection.

Camera Used:K Series film bodies (K1000, KM, KX, K2, K2DMD)

I recently purchased this lens after a long debate on whether I would ever use it very much or like the fish-eye effect.

I took it on a recent trip and really got to like it. I used it as my ultra wide angle lens and got some amazing landscape shots with it. As long as there is nothing close in the foreground and you keep your camera level to the horizon, you can keep the fish-eye effects to a minimum in landscape shots. I also used it in a couple cities, to get some nice “fish-eye” building shots.

Its fun to play with and you can experiment with the various built-in filters. I shoot film only (Colour and B&W), so the filters come in handy. There are four filters to choose from and a “none” position: Y48(Y2), Skylight, L39(UV), O56(O2). The filters are selected via a ring on the front of the lens, just inside the built in mini lens hood.

The 180 degree angle of view means you can get an incredible amount of image into your shot. Just remember to double check your cameras entire viewing area, as it’s very easy to get your fingers and other unwanted items in a shot due to the small size of the lens. There is not much in the way of protection with the very small built in lens hood, so you need to be careful with the exposed front element.

The slower f/4 aperture is fine for most daytime situations. The faster more costly A16/2.8, is better for low lighting shots.

Being a mid seventies Pentax K series lens, you get a quality built product that will last decades.

“Mr. Fish” is definitely becoming one of my favourite lenses.

Sample shots taken with the K17/4 Fish-eye. Photos are medium resolution scans from original slides.

I have had this lens for many years and always find a use for it from my film days (actually I still use film) to my K10D. It is a very forgiving lens and will take great images even with the distortion that you always need to keep in mind.

Here is a shot taken with this lens on my K10D today with the lens about 3 inches from the closest Sunflower and with the horizon in the center to minimize distortion.

I bought this lens in the late 70's or early 80's I think. I bought it from a large camera shop in San Francisco second hand. I really wanted a fish eye at the time, and it was very expensive. However, I had fun with it for a short time, and used it sparingly. I didn't realize how limited a fish eye would be for the type of shooting I was interested in then.

At any rate, its been sitting in it's case inside a large Tamrac bag with lots of other lenses for a very long time. I gave up the Pentax gear in favor of Canon EOS systems for several years, then bought a Point and shoot digital. I've been using point and shoot digitals for several years now, and haven't touched a film camera. Recently I acquired a digital SLR body, and really got interested in the hobby again. The point and shoot cameras were used just for business pictures or obligatory Holiday photos.

A couple of weeks ago, I was in Napa Valley, CA for some business, and had to go into San Francisco on Saturday. I was able to spend several hours walking the streets of Chinatown and North Beach eating and taking in the sights. I decided to arm myself with only the fish eye.

Saint Peter and Paul Cathedral became a favorite target once again. For years, I've been trying to get photos of that church when the light was just right, and finally I was in the right place at the right time. Chinatown still had many decorations up after Chinese New Year, and those were photogenic as well.

Anyway, despite the distortion of a fish eye, I got many excellent pictures of architecture, people on the streets and in the park. Shops and merchandise, lamposts, fire escapes, marquis', and everything else was fair game. The fish eye effect added some marvelous effects to many of the pictures, with dragon lamposts bending like crazy!

Despite my aging eyes and attempts to make sure everything was out of focus, nearly all of the shots came out sharp with great color and contrast. Nearly everything within a few inches of this lens is in focus. I was actually surprised at the quality of the images and all were most certainly a far departure from anything I was able to record on film in the past. I was very impressed with all the images from this lens with the exception of several with flare. Unfortunately, there's no way to add a hood to a lens with 180 degree field of view. I like flare in pictures sometimes, but with this lens, most of the flare episodes were unintentional and unwanted. However, if you have time to compose your shot, you can always extend a hand over the lens to cut down the brightness and eliminate the flare. But be careful, you really have to stretch to keep your hand out of the image!

I guess I could live without this lens (as I have it's 18mm super wide cousin which has no fish eye effect), but after spending an entire day with it and shooting over 300 pictures I wouldn't want to.

In conclusion, I enjoyed working with it in this manner so much, on the following day, I worked only with an SMC 35mm A lens. It's pretty amazing what your feet can do, and what your eyes can see when you're limited to a single "uninteresting" focal length. However, the SMC Pentax 17mm fish eye is about as interesting as you can get!